Pulley for brakes and the like



sept. '7,' 1926. 1,599,373 v E. ROBERTS PULLEY FOR BRAKES AND THE LIKE Filed Dec. 24, 1921 2 Sheets-Sheet 1 Sept. 7 1926."

E. ROBERTS PULLEY FOR BRAKES AND ,THE LIKE 2 Sheets-Sheet 2 Filed Dec. 24, 1921` f Patented sept. 7, 1926.

. UNITED sT-ATEs PATENT OFFICE.

EUGENE ROBERTS; or sALT LAKE CITY, UTAH, v'AssIefNm To THE WESTERN sTATEs MACHINE COMPANY, or sALT LAKE CITY, UTAH, A CORPORATION or UTAH.

PULLEY FOR BRAKES `AND THE LIKE.y

Application ma neceinbef 24, 192.1. serial No. 524,663.

This invention relates to certain improvements in brake pulleys such as are used for driving centrifugal machines in which the belt pulley is provided .with an interior 5 friction face 'adapted to be engaged by an interiorly arranged brake, and is intended to provide la construction whereby apositive circulation of air is maintained whenv the pulley is'in rotation to abstract from the i pulley the heat generated by the friction of the brake. shoes. I t will also be understood that the same principles of construction are applicable whether. the friction shoes are brake shoes or whether they are i used as clutches to drive the belt pulley.-A

Generally speaking the invention comprises a belt pulley'provide'd with an' inside friction face combined with internally vdisposed gripping shoes arranged to be Amoved 2o into engagement with said inside. face, .the pulley being provided with air-circulating passages so arranged as to direct @currents of air through the interior of the pulley for the purpose of conducting away the heat generated by friction. Thisand other features of the invention will be fully explained in the following specification and will be defined in the claims hereto annexed. v

In the drawin I have illustrated two different s ecit'lc orms embod ing the principles of t 's invention, in w ich: i

Figure 1v is a. vertical central section 1llustrating the application of the principles of this invention to the driving pulley of a centrifugal machine, portions of the centrifugal machine being broken awayv to permit large scale illustration. Figure 2 is a plan viewA of the brake and 'belt pulley partly shown in section.

' Figure 3 is a detail view of the interior construction of the-pulley showing the studs or .bosses which provide an air-circulating space inside the pulley. n

Fi re 4 is a to plan view illustrating a modified construction of pulley.

the same construction. f-

Figure- 6 is a vertical section of the flanged rim portionof the same form of pulley shown in Figures 4 and 5.

In Figure 1 I have illustrated in assembled relationship, one form -of brake and combined belt and brakepulley applied to a centrifu 4al machine of the type in which the centri ugal is suspended from a hollow a .gyratory suspension spindle 5, the bolt being mounted in upper andA lower socket' pieces 3 and 4 to permity gyration in all' di and lower solid section' 8, is suspended uponl this gyratory spindlefor rotation by suit-y able rotary bearings.

At its upper end the shaft section 7 is provided with an outwardly projecting circular flange 7"L to which thebelt pulley -10 is detachably secured by means of an in'- turned annular flange 1()a through the. medium of suitable fastening bolts 10b.

In this form of the invention the rim or peripheral portion of the pulley 1,0 is p"ro vided on its interior face with a series of in# wardly projecting bosses 11 forming, at-fre- (uentintervals, supports for a hardened steelv riction ring 12 which is forced into the upper -endof the pulley, and which is 'kept lfrom slipping circumferentially therein by means ol pro]ecti1g' ribs or bosses 13 whic pass between adjacent rows of lugs or bosses l1 to form an interlocking engagement to side the pulley. It will .be seen that this construction leaves an interior air-circulating space between the friction ring and *theI -hanger 1 by a supporting bolt se-cured to A prevent rotative slip of the friction ring intween the pulley rim and the inwardly" turned flange. By making these air circulating openings or passages 14 open outwardly it will be seenv that the tendency, dueto the centrifugal force of rotation, is

to expel the air through these outwardly ex- Figure 5 is a bottom plan view showing tending passages ,which air is drawn in at the top of the pulley. This circulation of the force the air into the spaces between the fricc tion ring and the outer member or rim of the pulley thereby increasing the circulating i action. Another means of assisting this acy tion comprises inclined vanes mounted' on fixed pivoted post 2j2`carried by the hanger.

the bottom of the flange l0a so that when the pulley rotates these vanes, arranged one .in advance of each circulating passage, act

to .create a partial' vacuum at the outlet end of the circulating passages tol reenforce the air circulation. H

So far as .this invention 1s concerned, the particular construction of thev brake shoe elements is immaterial. .For purposes illustratie however, I have shown a palr of brake s oes pivotally mounted by a ysort of gimbal joint element -in curved brake arms 21 which are fulcrumed upon a The outer faces ofthe brake shoes are shown covered with strips 29 of brake lining mate- I rial,.while the brake shoes are forced apart by the action of. toggle linksv23 engaged 1h13; a vertically movable toggle spreading li 24. The two free ends of the brake levers or arms are held together4 by a contractile spring 26. Other details are. deemed unnecessary sinc'efthis part of the construction-forms no part of the resent invention.

In Figures 4. to 6 I have illustrated a somewhat simpler form of the invention in which the brake pulley is so. constructed that the currents of air are blwn directly across the inside brake-engaging or frictional surface ofthe pulley, he pulley-rim in this case beling solid without the internal ailr-colingv vspaces shown in Figure l.

l Inl this form the pulley rim is provided with the inwardly turned flange 31.

located a slight distance above the'bottom edge of the pulley rim. Beneath the flange -is arranged a series of inwardly projecting vanes 32 -ntendedto form, in connection with the lian e and the pulley rim, air-com pressing poc ets. Preferably,`in orderto get a more effective air compressing action,

these vanes 32 are inclined instead of being laid out on the radii of thev pulley, and this inclination is preferably'such that the lower edge and the inner end of each vane `is in advance of their upper and their outer portiin, respectively, as shown in Figures In-each pocket, ythat is', in the angle be-l tween each vane, the outer rim and the inward flange, I provide anV air-circulating passage or orifice as shown lat33 such oice preferably being larger at its lower or;

intake end than at itsfupper or out-.take end, and being also preferably-inclined from' bottom to top ina rearward and out- -ward direction to assist in `more efectually taking in the air and Ldirecting it with appreciable force over the inside face f the pulley rim. y

Duringy the normal operation or rotation of the pulley the surrounding air is compressed by reason of its own inertia in opv of the pulley, 'said pull I actin position to the rapidly moving vanes so as to be forced through the air circulatingjori-. fices or passages in 'steady streams, there.

by extracting the heat from that portion of the pulley exposed tothe frictional contact of the'brake shoes with thel result that f the overheating of the pulley, with consequent injury to the belt and to the brake lining material, 'is avoided. The flaringor diagonal arrangementfof the air-circulating openings'tendsto utilize the centrifugalG force to induce a circulation'of'air currents,

though where the maximum cooling action is desiredthe vanes shouldbe used also.

What I claim is: A l. A combined driving pulley and brak v. for a centrifugal machine comprising an annular band provided with aninwardly projecting attaching flange, interiorl disposed shoes movable into and out' o frictional engagement with the insidei surface being provided l adjacent'to said flange W h avseries of inseries of air currents through the interior -of the-pulley when rotating to :bszlract het sai ys oes,su -1- generated'by the friction o stantiallyas described. t

2. A combined driving pulley and brake for centrifugal machines, embracing in its clined air passages arranged to maintain a construction an annular inwardly flanged' driving pulley provided with a series of airV circulating passages adjaeiitl to said flange,

a coactin series ofyanes arrangedon said pulley a jacent to the air circulating pas'- sages to force air therethrou h, and interiorly disposed shoes movable into .frictional pullesubstantially as described. 1 3. n an expansible brake, the combination of an external pulley, internally disposed shoes arranged to be expanded against the inside surface of said pulley to form' .engagement with the inside wall ofq saidl tiona engagement with said pulley, the lpulley b eing provided with a seriesof bl1queopeningsso inclined as maintain a positiveflow of air current b y centrifu al 'action against the shoe-engage face of te pulley when the pulley rotates and thereby abstract heat generated by the. lcgitact with the shoes,-

substantially as descri 5; A brake compris" coacting shoes movable-into and out of fricmg a romane' pulley.

tional engagement with said pulley, 'said pulley being providedk with a series of air j circulating openings, arranged to direct air' currents against the shoe-engaged' surface of the pulley, a series of 'coacting vvanes :ar-

ranged to deflect air through said openings forced through said openings flows over the interior of the pulley to abstract heat generated bythe friction of said shoes, substantially as described.

6. The ,combination of a rotatable belt pulley, interiorly disposed shoes movable into frictional engagement with the inside surface of the pulley, a series of inclined,

vanes arranged at intervals around the inside of said pulley offset to the plane of said shoes, said pulley being provided with a series of air circulating passages between the vanes and the pulley rim to direct air. currents through the pulley and thereby abstract therefrom heat generated by the friction of said shoes, substantially as described.

7. The combination of a rotatable belt pulley embracing a peripheral rim provided with an inwardly projecting flange, interiorly disposed brake shoes movable into frictioaxal engagement with the inside face of said pulley above said flange, a series of vanes arranged beneath said ange to form a series of air-circulating members when the pulley rotates, said pulley being provided with a series of air-circulating holes close to said vanes to produce flow of air currents across said rim interiorly thereof in order to abstract heat therefrom, substantially as described.

8. In a device of the class described, the combination of a rotatable pulley coacting interiorly arranged friction shoes movable into frictional engagement therewith, said pulley being provided with a series of inclined air circulating passages having their outlet ends farther from the centre of the pulley than ltheir intake ends thereby utilizing the centrifugal force ofrotation to induce circulation of air, said passages being arranged to direct currents of air through the pulley to abstract heat generated by frictional engagement with said shoes, substantially as described.

In witness whereof, I have subscribed the above specification.

EUGENE ROBERTS. 

